Sony Corporation

Toshimichi Nishimura

Seisuke Yamanaka

Fumio Nagumo

Masaru Shimada

Takashi Noguchi

Atsushi Kikuchi

Hiroaki Isono

An information-supply control apparatus and method uses a cable modem. The cable modem has one I/O connector attached to a coaxial cable coupling the cable modem with the cable system's head end. Another I/O connector is attached to a subscriber's local area network (LAN). The cable modem prioritizes its processing of packets as follows. Packets received from the cable system head end that are addressed to devices on the subscriber LAN are given the highest priority. Packets received from the cable system head end that are addressed to the cable modem itself are given the second highest priority. Packets received from the subscriber LAN that are to be transferred to the coaxial cable are given the third highest priority. Finally, packets that are received from the subscriber LAN that are to be transferred back to the subscriber LAN are given the fourth highest priority. The cable modem also determines whether a received packet has overflowed its allocated buffer. Upon detecting buffer overflow, the cable modem discards the overflow data.

Cable modem control method giving priority to packets from the cable head end over packets from the subscriber LAN

An n-th degree switched capacitor filter having transfer characteristics expressed by a transfer function H(Z) can be configured by expanding the transfer function H(Z) to an n-element linear simultaneous state equation of n state voltages inclusive of an output voltage. The coefficients of the linear state equation a.sub.11 to a.sub.n2, b.sub.11 to b.sub.nn are determined in a range within which the filter circuit can be configured by hardware and further each state voltage is below a maximum output voltage. In practice, the filter is configured by plural leapfrog type differential operational amplifiers having base capacitors C.sub.o, plural transmission gates, and plural electric charge transfer capacitors C.sub.T so as to determine each coefficient on the basis of ratios C.sub.T /C.sub.o. The filter is realized by a monolithic integrated circuit (IC) and provided with a higher signal-to-noise (S/N) ratio and a wider dynamic range without deteriorating electrical characteristics and increasing cost.

Method of configuring an n- th degree switched capacitor filter

A drive circuit comprises output transistors of complementary type serially coupled to each other between voltage supply terminals, auxiliary transistors of complementary type which have base electrodes respectively connected to the serial connection point between the output transistors and which are serially coupled between the respective base electrodes of the output transistors, and resistors serially coupled between the voltage supply terminals with their connection point coupled to the connection point of the auxiliary transistors. An input clock signal is supplied to the respective base electrodes of the output transistors via coupling capacitors, and an output clock pulse is derived from the serial connection point between the output transistors.

Drive circuits for driving digital circuits with a clock signal

A white balance control circuit for an encoded composite color television signal is disclosed in which three primary color signals of green (G), blue (B) and red (R) are matrixed to be mixed color signal components, color difference signals of R-G and B-G are provided from the mixed color signal components, and gain control circuits provided on the signal transmission paths of two primary color signals of R and B are so controlled in their gains that the color difference signals become zero, when the white balance adjustment is done.

White balance control circuit

A solid state color television camera having a solid state image sensing device and an optical color filter. In this case, the color separating characteristics of the color filter is so selected that when a predetermined horizontal scanning line is scanned, from the solid state image sensing device there are obtained a red color signal and a luminance signal of the standard system sequentially and alternately, and from a horizontal scanning line adjacent the above horizontal scanning line there are obtained a blue color signal and luminance signal. Also, as the high band component, which constitutes the above luminance signal, the high band component of a composite video output signal, which includes the primary color signal and luminance signal produced by scanning the above horizontal scanning line, is utilized. Further, by scanning the respective horizontal scanning lines, different color difference output signals obtained at every one horizontal scanning line are made in simultaneity and based upon the color difference output signals and luminance signal there is produced a color video signal of the standard system.

Solid state color television camera

A solid state color camera having an image sensing device which has a plurality of image sensing cells aligned in both the horizontal and vertical directions, an optical filter which produces three primary color separated images on the image sensing device, a circuit which reads out an image signal as to satisfy an interlaced signal reading system of a standard television signal, the image signal being comprised of a luminance signal and a chrominance modulated carrier signal, a circuit which supplies a carrier signal to the reading out circuit, the carrier signal being selected approximately equal to or half of a standard color sub-carrier frequency, and a circuit selecting vertical and horizontal frequencies of a read out image signal.

Solid state color camera

A color camera system is disclosed in which a dot-like signal which appears on a TV screen caused by a processing error is effectively eliminated. A pick up device with a color coding filter derives composite signals containing color components modulated at a frequency f.sub.s where the composite signals are obtained in opposite phase line by line. An adder circuit is provided to mix the composite signals obtained from two adjacent lines. A detector detects the 2nd harmonic of f.sub.s from the mixed composite signals. A dual gate MOSFET is provided to suppress a high frequency region of a luminance signal which is derived from the composite signals in response to the detected 2nd harmonic of f.sub.s.

Color camera system

A color signal modulating system for a color television camera having two CCD's as image pick-up devices for converting optical images into two color signals at alternate scan lines and into a third color signal at consecutive scan lines. Means are provided for developing two color difference signals, one of which is developed from alternate lines of scan. The color difference signals are used to modulate a carrier signal at alternate lines, and means are provided to derive sequentially modulated first and second color difference signals simultaneously at an output of the signal modulating system.

Color signal modulating system

In processing a video signal, vertical correlation is utilized between video signals of successive line intervals. Video signals from the two line intervals are examined, their existences, polarities and magnitudes between them. If both signals exist with the same polarity, a smaller signal in magnitude is derived at a system output and otherwise no signal appears at the output. This system can be applied to a color television camera circuit.

Signal gating system

A solid state television camera having a solid state image sensing device and an optical color filter. The color separating characteristics of the color filter are so selected that when a predetermined horizontal scanning line is scanned the solid state image sensing device produces a standard red color signal and a luminance signal sequentially and alternately, and when an adjacent horizontal line is scanned, a blue color signal and luminance signal are produced in the same manner. In this way, different color difference output signals are simultaneously obtained at every horizontal scanning line, and based upon the color difference output signals and luminance signal, there is produced therefrom a standard color video signal.

Growing community of inventors

Tama, Japan

Toshimichi Nishimura